Calibrated slot cutter

ABSTRACT

A calibrated slot cutter adapted to be inserted into a small diameter pipe for cutting a calibrated slot or groove at a position in the pipe remote from its ends wherein the slot cutter apparatus includes a drive unit, an extension unit, and a cutter assembly unit which may be connected together to form the cutter apparatus of the present invention. Such units are releasably coupled together to facilitate transportation of the unit to remote locations and, extension units of different lengths may be used to position the cutter unit at the desired distance inwardly from the open end of the pipe.

United States Patent H [111 3,868 887 Sorenson Mar. 4, 1975 CALIBRATED SLOT CUTTER Primarv Evaminer-Andrew R. .luhasz 76 I t Al A.S ,58llFl' l 1 men or grg zg dmmgo Assistant E.\GHIHII'Z. R. Billnsky {22] Filed: Jan. 18, 1973 57 ABSTRACT [2!] App]. No.: 324,676 A calibrated slot cutter adapted to be inserted into a small diameter pipe for cutting a calibrated slot or [57] U S a 90/12 B 83/5 9WD; 8 groove at a position in the pipe remote from its ends 6 823': wherein the slot cutter apparatus includes a drive unit e Fie'ld R DIG an extension unit, and a cutter assembly unit which may be connected together to form the cutter apparatus of the present invention. Such units are releasably [sh] References Cited coupled together to facilitate transportation of the unit to remote locations and, extension units of differ- LNITED STATES PATENTS ent lengths may be used to position the cutter unit at II Z; g i tttt tt t t t QO H the desired distance inwardly from the open end of the All l0 19 cc 'mun ct at i r l 3.464.3l3 9/1969 Shay ct ul. i t .r 90/12 pipe 311N446} 11/1971 Brincy et all r. 90/12 4 Claims, 8 Drawmg Flgures PMENTEU 4 5 SHKEI 3 0F 3 TO CABLE TELESCOPING DRWE SHAFT ,lzo me 1 C ALIBRATED SLOT CUTTER BACKGROUND OF THE INVENTION In inspecting pipe and other metal objects for defects or flaws in the pipe by electro-magnetic or ultrasonic testing devices, it is necessary to calibrate the flaw detection device with a flow of known characteristics. Thus, slots, notches or grooves as they are sometimes called are cut in a length of pipe and then used to calibrate the flaw detection apparatus. Such simulated flaws or notches must be accurately milled or cut in the pipe to accurately calibrate the flaw detection device.

The typical problems encountered in milling or cutting a simulated flaw or notch in a metal object are increased substantially when that flaw is cut in tubular goods and even more so as the diameter of the tubular goods is reduced. Thus, it has been very difficult to cut accurately calibrated flaws in relatively small diameter pipe, such as pipe having an inside diameter as small as 3 inches.

DESCRIPTION OF THE PRIOR ART The prior art devices for cutting a simulated groove or notch in a tubular member to calibrate flaw detection equipment provide very little adjustment or variation in the location that the groove or notch can be placed relative to the end of the pipe. Further, such prior art devices have problems with providing a positive connection between the notch cutting device and the piece in which the notch is cut. Also, the prior art devices are not suitable for use in small diameter pipe of approximately 3-inch inside diameter.

SUMMARY OF THE PRESENT INVENTION The present invention provides a new and improved calibrated slot cutter for cutting or milling a notch, slot or groove in a workpiece such as a tubular pipe wherein the device comprises a plurality of units which are releasably connected together to facilitate positioning the cutter assembly at the desired location in the tubular member relative to an end and further, such device includes a means for positioning the cutter in the tubular member and also for providing a positive locking connection between the cutter housing and the pipe. The improved locking apparatus of the device of the present invention is particularly suitable for use in small diameter pipe and especially for providing contact between the cutter housing and such small diameter pipe.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation of the calibrated slot cutter of the present invention;

FIG. 2 is an end view of the calibrated slot cutter showing the motor housing;

FIG. 3 is a sectional view taken on line 33 of FIG. 2 showing details of the construction of the calibrated slot cutter;

FIG. 4 is a longitudinal sectional view taken on line 44 of FIG. 2 showing further details of the construction of the apparatus of the present invention;

FIG. 5 is an end view of the end of the device opposite from the motor housing showing the locking means for securing the cutter in a tubular member;

FIG. 6 is a transverse sectional view taken on line 66 of FIG. 1 showing details of the cutter assembly;

FIG. 7 is a view taken on line 7--7 of FIG. 6 showing further details of the cutter assembly; and

FIG. 8 is a view showing the apparatus for securing the slot cutter to the extension of a pipe.

DESCRIPTION OF THE PREFERRED EMBODIMENT Briefly, the calibrated slot cutter apparatus of the present invention comprises the longitudinally extending tubular housing designated generally H in FIG. I of the drawings with the drive motor M affixed to one end of such housing and with the cutter designated generally C projecting from the side of the tubular housing adjacent the opposite end. As shown, such housing comprises a forward section or drive unit D, a center extension unit E and the terminal unit A in which the cutter apparatus is housed.

As shown in FIG. 3 of the drawings, each of the units D, E and A which, when joined together in a manner to be described hereinafter. comprise the housing H, are provided with a circumferentially extending tubular body ll, 12 and 13, respectively. The forward drive unit D is provided with a front end piece 15 which is se cured to the tubular housing 11 by screws or other suitable means. As shown, a shoulder or circumferentially extending annular recess 15' is provided in one edge of the end plate 15 for receiving the end of the tubular housing 11.

The cutter drive gear box which houses the right angle gear drive connecting the motor M and the cutter C will be described in detail hereinafter is mounted in the gear drive housing I7 which is secured in the drive unit D adjacent the front end 15 by means of screws I8 or other suitable releasable connecting means. The transversely extending shaft support plate 20 is provided in the drive unit D intermediate the front end 15 and the rear end member 22. The member 22 is a discshaped member having an annular flange or projection 24 thereon which forms a pair of annular shoulders 26 and 27 for receiving the surrounding tubular housing members 11 and 12, respectively.

Also as shown in FIG. 4 of the drawings, the center extension unit E includes an intermediate transversely extending plate 30 and an end piece 31 having a circumferentially extending annular projection 32 forming shoulders 33 and 34 for receiving the adjacent ends of the tubular housing pieces 12 and 13, respectively (FIG. 3). The cutter assembly unit A is provided with a circular end piece 35 having an annular shoulder 36 formed thereon for receiving the end of the housing 13.

Also shown in FIG. 3 of the drawings are the motor drive shaft 40, the cutter drive shaft 41 and the vertical feed shaft 42. The vertical feed shaft 42 is shown rotatably mounted in suitable bearings 43 carried in an opening 44 in the end plate 15 with additional bearing assemblies 45, 46, 47 and 48 mounted in openings 45a, 46a, 47a and 48a in the various transversely extending plates or end members 20, 22, 30 and 31. Thus, it will be seen that when the housing units D, E, and A are secured together the openings 43, 45a, 46a, 47a and 480 are aligned axially relatively to one another for receiving the vertical feed drive shaft 42 which is carried in the various bearing assemblies heretofore mentioned. Further, as shown in the drawings, the drive shaft 42 is provided with splined couplings 44s which are positioned between the bearing assemblies 45 and 46 and also between the bearing assemblies 47 and 48 to enable the three units, D, E and A to be releasably connected together.

As shown in FIG. 3 of the drawings, the vertical feed drive shaft 42 is provided with a pair of longitudinally spaced worm gear segments 50 which operably engage the gears 51 which are carried on the shafts 53 so as to provide a right angle drive for rotating the shafts or screws 53 upon rotation of the vertical feed drive 42. Each of the screws 53 is threadedly connected in the inverted U-shaped carriage support 56 in which the cutter apparatus C is mounted. Rotation of the screws 53 by the drive 42 causes such carriage support 56 to be moved vertically upwardly or downwardly, depending upon the direction of rotation of the drive shaft 42. As shown in the drawings, a splined connection 57 is provided in the draft shaft 42 between the longitudinally spaced worm gears 50. Also, holding blocks 59 are secured on the inner side of the tubular housing 13 for supporting the shaft 42 in suitable bearings 60 and for also supporting the threaded shafts 53 which are shown positioned in openings 62 in such blocks 59 with slip springs 64 provided for holding the shafts 53 in such opening 62. As seen in FIGS. 3 and 6 of the drawings, the threaded screws 53 are received in threaded nuts 66 which are threaded into suitable openings 67 in the carriage support 56. Also, as shown in FIG. 6 of the drawings, each block 59 has a curved upper surface 590 which is curved to the same radius as the tubular housing 13 and is secured therein by means of screws or other suitable securing means. The gear drive 51 is shown supported on the screw shaft 53 and is secured thereto by means of splines or lock screws (not shown) as may be desired so as to drive the screw 53 as the drive gear 51 rotates.

Referring again to FIG. 3 of the drawings, the motor drive shaft 40 is provided with a worm gear section 70 which drives the gear 71 carried on the drive shaft 41. The worm gear 70 and the gear 71 form a right angle gear drive apparatus for driving the shaft 41 at right angles with respect to the drive shaft 40 of the motor M. Suitable bearings 73 and 74 are provided in openings 75 and 76 of the right angle drive housing 17. The opening or bore 76 is provided with a counter bore 77 for receiving the bushing 78 in which the gear 73 is carried. Also, it will be appreciated that suitable bearing means (not shown) are provided for supporting and aligning the motor drive shaft 40 with respect to the right angle gear mechanism.

As shown in FIG. 3, the cutter drive 41 extends through openings 80, 81, 82 and 83in the intermediate plates or end plates 20, 22, 30, and 31, respectively. Each of such passages is provided with bearings 85 for rotatably mounting the drive shaft 41 therein. Also, splined couplings 86 are provided in the shaft 41 to enable the various units D. E and A to be releasably coupled together. The shaft 41 is provided with a flexible shaft portion 41a which is connected to a drive pin 41b which drives the cutter as will be described in detail hereinafter. Such drive pin is mounted in bearing 87, carried in bearing support blocks 88 on the carriage support 56. The flexible shaft portion 410 is provided to accommodate misalignment between the axis of the pinion drive 41b and the axis of the shaft 41 due to vertical offset as a result of movement be it vertical adjustment mechanism in the A unit.

As shown in FIG. 6 of the drawings, the blocks 59 are also provided with suitable openings 59a and 59b for receiving the vertical feed or adjustment shaft 42 and the lock drive shaft 90 which will be described in detail hereinafter.

The carriage support 56, as shown in FIG. 6 of the drawings, comprises an inverted U-shaped channel member carried by the screws 53. Such inverted U- shaped channel 56 has longitudinally extending slots or grooves 56a provided on the inner sides of the downwardly extending or depending arms 561) which form ways for receiving the guides 92 which support the cutter carriage 94 and which guide the movement of such cutter carriage longitudinally of the tubular housing A. Such cutter carriage 94 is provided with a pair of rollers 98 which are mounted on shafts 980. Such rollers 98, as shown in FIGS. 6 and 7 of the drawings, are arranged in pairs with one pair of rollers on each side of the cutter carriage 94 and with such rollers arranged so as to engage the under surface 566 of the horizontal center portion of the inverted U-shaped channel 56. With the guide members 92, shown in FIG. 7, arranged in pairs on opposite sides of the cutter carriage 94, adjusted so as to fit properly in the ways 56a, the rollers 98 will engage the surface 56c to facilitate movement of the cutter carriage 94 longitudinally along the inverted U- shaped channel member 56 in a manner to be described in detail hereinafter.

The cutter carriage 94 is provided with a depending support member 100 which supports the cutter shaft 102 on which the cutter blade or milling tool 103 is carried. Such support 100 has guides 92 connected thereto which extend diagonally upwardly and ride in the ways 56a in the inverted channel member 56. Such guides 92 have adjustable set screws 100a and lock screws 10% for aligning and positioning the guides 92 in the ways 56. Also, the support 100 is provided with a bore 101 for receiving the cutter shaft 102 and a counter bore 104 for receiving the bearing 105. The bearing 106 which is carried in the bearing support 107 also supports the shaft 102. Such bearing support 107 is secured to the depending portion 100 of the cutter carriage 94 by screws 95, or other suitable securing means. Such shaft 102 is provided with a threaded portion 102a which receives a lock nut 110 which locks the plate 111 on the shaft 102. As shown, the plate 111 is provided with a counterbore 1110 which fits over the shoulder 1020 on the shaft 102. The cutter 103 is provided with an opening or bore through which the shoulder portion 1020 tits and also such shaft 102 is provided with annular flange 107d of substantially the same diameter as the plate 111 so that with the cutter 103 positioned on the shaft 102 and plate 111 locked adjacent the cutter blade 103 lateral support is provided on either side of such blade 103. The shaft 102 is provided with wrench faces 102s at the end 102d. Gear 115 is secured to the shaft 102 adjacent end 102]. Such gear 115 is connected to the shaft l02fby means ofa spline or other suitable connecting means and engages the worm gear 116 which is mounted on the shaft 117. As best seen in FIG. 7 of the drawings, the shaft 117 is mounted in bearing 118 and 119. The bearing 119 is held in position in the bore by means of the sleeve 121 and the bearing 118 is positioned adjacent an annular shoulder 122 formed in the bore 120. Such bearing 118 is held against that shoulder by means of the sleeve 123.

The worm gear drive shaft 117 is connected to the shaft member 41b which in turn is operably connected through the right angle gear drive to the motor M for driving the cutter blade 103.

As shown, the housing A is provided with a window or aperture 130 through which the cutter blade 103 extends to engage the adjacent wall of the tubular member in which the notch or groove is cut.

FIG. 4 of the drawings shows the lock drive shaft 90 which extends longitudinally of the tubular housing H. Such shaft 90 is shown mounted in bearings 90a in each of the transversely extending plates or end members I5, 20, 22, 30, 32 and 35, respectively. Also, as shown, the shaft 90 is provided with splined connection 90b to facilitate separation of the housing H into the various component units A, E and D as described hereinabove.

As shown in FIGS. 4 and S of the drawings, the lock drive shaft 90 is provided with a first gear means 92 which is positioned to the rear of the back plate 35 in the cutter drive unit A. Such gear intermeshed with a second gear 93 which is rotatably mounted on a shaft 94 which is secured in the plate 35. The pinion gear 94 engages the rack gear 96 so that rotation of such gear 94 moves the rack 96 transversely of the circular end plate 35. As shown, such rack 96 is provided with a pair of slots 960 which receive pins 96b on which are provided heads 96c which retain the rack gear 96 in position adjacent the plate 35 and which limit the radial movement of such rack gear 96 by virtue of the length of the slots 96a. The rack gear 96 is also provided with a pad or projection 98p which is provided for engaging the inner surface of the tubular member in which the cutter apparatus of the present invention is used to cut a notch or groove. Such projection 98p is mounted on a rod 98q connected to the rack drive 96. Rods of different lengths can be used for securing the assembly A in various diameter size pipe. Also, the plate 35 is provided with a pair of lugs 99 which are positioned to be spaced approximately 45 from each other and from the position of the lug 98p so as to provide a 3-point contact in the pipe or tubular member in which the tubular housing A is used.

FIG. 4 also shows the shaft 140 provided for moving the carriage support 56 longitudinally relative to the opening I30 for cutting a longitudinally extending groove or notch with the cutter blade 103. Such shaft I40 is shown mounted in bearings 1400 in each of the transversely extending plates 15, 20, 22, 30 and 31, respectively. Such shaft 140 is provided with splined couplings 140k and 140C for disconnecting the various units comprising the housing H. As shown, the shaft 140 is provided with a universal connection 14] at its inner end with a telescoping connection 142 affixed to the shaft 140 by means of the universal l4I. Such telescoping shaft I42 is provided with interior threads for receiving the threaded pin 143 that is connected to the cutter block 56 by means of a swivel connection 145. With the threaded sleeve 142 receiving the threaded shaft 143, it will be appreciated that rotation of such sleeve 142 by the universal joint 141 will cause the shaft 143 to move longitudinally relative to the sleeve 142, the direction of such movement depending of course upon the direction of rotation of the shaft 140. Further, it will be appreciated that with the swivel connection and the universal connection 141, the carriage block 156 may thus be moved both longitudinally and vertically with respect to the housing H.

In the operation of the calibrated slot cutter device of the present invention, the various components such as the motor drive unit D, the extension unit E and the cutter assembly A are connected together with the various drive shafts 41, 42, 90, and 140 connected together with their respective spline connections to form the complete housing H. Such tubular housing H is then inserted into the pipe or tubular member in which callbrated groove or notch is to be cut with the cutter C retracted radially inwardly relative to the housing H so as not to engage the interior surface of the pipe during insertion.

Once the tubular housing H has been inserted to the desired position, the block drive shaft is rotated to drive the rack mounted projection 98 radially outwardly into engagement with the inner surface of the tubular member T. With the projection 99 engaging the inner surface on the tubular member T on the opposite side of the axis of said tubular member from the projection 98p, the housing H may thus be firmly locked in position in the tubular member T.

Assuming the tubular housing H is thus locked in position in the tubular member T for cutting the calibrated groove or slot, the carriage support 56 is preferably positioned at the rear end of the aperture or window I30 as shown in FIG. I of the drawings. With the motor running and driving the cutter C, the vertical feed shaft 42 is turned counterclockwise as viewed in FIG. 2 to lower the carriage support 56 so as to cause the cutter 103 to engage the inner surface of the tubular member T for cutting the groove or notch therein.

In the preferred form of this invention, the gear drive mechanism for raising and lowering the carriage support 56 by means of the vertical feed arrangement, the worm gear and drive gear which rotate the screws 53 is sized so that each revolution of the vertical feed shaft 42 will provide 0.0025 inch variation in elevation of the cutter blade 103. Thus, the depth of the groove or notch may be carefully controlled by counting the number of turns of the shaft 42 after the cutter 103 has first engaged the inner surface of the tubular member T.

The connecting pins or members 98p and 99 are electrically insulated so as not to make contact with the surrounding pipe in which the notch is cut. An ohm meter (not shown) is attached to member T and cutter assembly so that when the circuit makes contact with the pipe, the circuit is completed and resistance is registered on the ohm meter. After the cutter 103 has been lowered to the prescribed depth for the calibrated cut, then with the motor still driving the cutter 103, the horizontal feed drive shaft is rotated clockwise as viewed in FIG. 2 of the drawings to cause the telescoping sleeve 142 to draw the threaded shaft 143 into such sleeve I42 and thereby move the cutter carriage 94 toward the front end of the housing H. In the preferred form of this invention, the threaded connection formed between the threaded shaft 143 and the threaded sleeve 142 is such that each revolution of the shaft 140 causes the carriage 94 to travel 0.050 of an inch. Thus, upon rotation of the horizontal feed shaft 140 the cutter carriage 94 is caused to move in the ways 56a of the inserted U-shaped channel 56 so as to move the cutter blade I03 longitudinally relative to the tubular housing H for cutting a longitudinal groove in the surrounding tubular member T. After the desired cut has been made with the depth and length of such groove or notch being carefully calibrated by means of the apparatus hereinabove described, the vertical feed shaft 42 is rotated clockwise as shown in FIG. 2 of the drawings to cause the screws 53 to raise the carriage support 56 and thereby lift the cutter 103 free of the tubular member in which the groove has been cut and retract it into the tubular housing H. Thereafter, the lock shaft 90 is rotated in a counterclockwise direction as shown in FIG. 2 of the drawing to disengage the lock pin 98 from the inner surface of the tubular housing and thereby enable the tubular housing H to be withdrawn from such tubular member T.

FIG. 8 shows an apparatus for securing the tubular slot cutter to the extension of a pipe and includes a strap 150 which extends around the pipe or tubular member T and which is provided with a suitable latch for connecting the strap ends together. A bar 152 extends longitudinally of the cutter assembly and has an inverted U-shaped saddle member 153 connected by a vertical rod 154 to the bar 152. Such inverted U- shaped member 153 is of substantially the same radius as the body of the cutter assembly A so as to fit snugly thereon. An extension piece E is connected to the rack drive 96 and to one end of the bar 92 so that the same lock drive mechanism can be used for locking the cutter assembly A to the pipe. The lock drive mechanism for securing the cutter assembly in the pipe is operated substantially the same way when secured to the extension of the pipe with the bar and strap arrangement described herein.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

What is claimed is:

l. A cutter device for cutting a calibrated notch or groove in a substantially cylindrical workpiece member comprising: i

a. a longitudinal extending tubular housing adapted to be inserted into the workpiece member, said tubular housing including a motor drive unit at one end thereof and a cutter assembly unit at the other end thereof, said tubular housing substantially enclosing said cutter assembly unit;

b. motor means mounted adjacent said motor drive unit. said motor means being mounted externally of said tubular housing;

c. said cutter assembly unit comprising:

1. axially spaced holding block means attached to said tubular housing;

2. carriage support means supported by said holding block means and relatively movable thereto transversely of said tubular housing;

3. a cutter carriage supported by said carriage support means and relatively movably thereto longitudinally of said tubular housing;

4. cutter drive means in said cutter carriage;

5. cutter means carried by said cutter drive means;

d. means for moving said carriage support means with respect to said holding block means transversely of said tubular housing;

e. means in said motor drive unit for actuating said means for moving said carriage support means transversely of said tubular housing;

f. means for moving said cutter carriage with respect to said carriage support mefins longitudinally of said tubular housing;

g. means in said motor drive unit for actuating said means for moving said cutter carriage longitudinally of said tubular housing;

h. a first drive shaft rotatably mounted in said motor drive unit operably connected to said motor means;

i. a second drive shaft rotatably mounted in said cutter assembly unit and operably connected to said cutter drive means;

j. means for releasably connecting said first and second drive shafts together for driving said cutter drive means with said motor means; and,

k. means for expansively locking said tubular housing in the cylindrical workpiece.

2. The invention of claim 1 wherein said means for expansively locking said tubular housing to the cylindrical workpiece member includes a slotted rack gear drive operably connected to a gear drive shaft extend ing through said motor drive unit.

3. The invention of claim 1 further including:

motor extension means intermediate said motor drive unit and said cutter drive means for operably connecting said cutter assembly unit at a position in the cylindrical workpiece member remote from said motor drive unit;

splined longitudinal drive extension means for operably connecting said means in said motor drive unit for actuating said means in said cutter assembly unit for moving said cutter carriage longitudinally within said tubular housing to said means in said cutter assembly unit for moving said cutter carriage longitudinally within said tubular housing when said cutter assembly unit is remote from said motor drive unit; and

splined extension means for operably connecting said means in said motor drive unit for transversely moving said carriage support in said cutter assembly unit for moving said cutter means transversely relative to said tubular housing to said means in said cutter assembly unit for moving said carriage support means transversely relative to said tubular housing when said cutter assembly unit is positioned remotely in the cylindrical workpiece member relative to said motor drive unit.

4. The invention of claim 3 wherein said longitudinal drive extension means includes:

an outer sleeve pivotally connected with said motor drive unit; and

an inner portion pivotally connected with said cutter carriage, said inner portion being threadedly mounted with said outer sleeve.

i i l 

1. A cutter device for cutting a calibrated notch or groove in a substantially cylindrical workpiece member comprising: a. a longitudinal extEnding tubular housing adapted to be inserted into the workpiece member, said tubular housing including a motor drive unit at one end thereof and a cutter assembly unit at the other end thereof, said tubular housing substantially enclosing said cutter assembly unit; b. motor means mounted adjacent said motor drive unit, said motor means being mounted externally of said tubular housing; c. said cutter assembly unit comprising:
 1. axially spaced holding block means attached to said tubular housing;
 2. carriage support means supported by said holding block means and relatively movable thereto transversely of said tubular housing;
 3. a cutter carriage supported by said carriage support means and relatively movably thereto longitudinally of said tubular housing;
 4. cutter drive means in said cutter carriage;
 5. cutter means carried by said cutter drive means; d. means for moving said carriage support means with respect to said holding block means transversely of said tubular housing; e. means in said motor drive unit for actuating said means for moving said carriage support means transversely of said tubular housing; f. means for moving said cutter carriage with respect to said carriage support means longitudinally of said tubular housing; g. means in said motor drive unit for actuating said means for moving said cutter carriage longitudinally of said tubular housing; h. a first drive shaft rotatably mounted in said motor drive unit operably connected to said motor means; i. a second drive shaft rotatably mounted in said cutter assembly unit and operably connected to said cutter drive means; j. means for releasably connecting said first and second drive shafts together for driving said cutter drive means with said motor means; and, k. means for expansively locking said tubular housing in the cylindrical workpiece.
 2. carriage support means supported by said holding block means and relatively movable thereto transversely of said tubular housing;
 2. The invention of claim 1 wherein said means for expansively locking said tubular housing to the cylindrical workpiece member includes a slotted rack gear drive operably connected to a gear drive shaft extending through said motor drive unit.
 3. The invention of claim 1 further including: motor extension means intermediate said motor drive unit and said cutter drive means for operably connecting said cutter assembly unit at a position in the cylindrical workpiece member remote from said motor drive unit; splined longitudinal drive extension means for operably connecting said means in said motor drive unit for actuating said means in said cutter assembly unit for moving said cutter carriage longitudinally within said tubular housing to said means in said cutter assembly unit for moving said cutter carriage longitudinally within said tubular housing when said cutter assembly unit is remote from said motor drive unit; and splined extension means for operably connecting said means in said motor drive unit for transversely moving said carriage support in said cutter assembly unit for moving said cutter means transversely relative to said tubular housing to said means in said cutter assembly unit for moving said carriage support means transversely relative to said tubular housing when said cutter assembly unit is positioned remotely in the cylindrical workpiece member relative to said motor drive unit.
 3. a cutter carriage supported by said carriage support means and relatively movably thereto longitudinally of said tubular housing;
 4. cutter drive means in said cutter carriage;
 4. The invention of claim 3 wherein said longitudinal drive extension means includes: an outer sleeve pivotally connected with said motor drive unit; and an inner portion pivotally connected with said cutter carriage, said inner portion being threadedly mounted with said outer sleeve.
 5. cutter means carried by said cutter drive means; d. means for moving said carriage support means with respect to said holding block means transversely of said tubular housing; e. means in said motor drive unit for actuating said means for moving said carriage support means transversely of said tubular housing; f. means for moving said cutter carriage with respect to said carriage support means longitudinally of said tubular housing; g. means in said motor drive unit for actuating said means for moving said cutter carriage longitudinally of said tubular housing; h. a first drive shaft rotatably mounted in said motor drive unit operably connected to said motor means; i. a second drive shaft rotatably mounted in said cutter assembly unit and operably connected to said cutter drive means; j. means for releasably connecting said first and second drive shafts together for driving said cutter drive means with said motor means; and, k. means for expansively locking said tubular housing in the cylindrical workpiece. 